Random Feature Selection

Random Feature Selection

I met with a gentleman today who needed to select random streets in Wilmington in order to do a field survey of urban forestry there. Here are the steps we took to do so:

-Use Excel and the RANDBETWEEN function to generate random numbers in a range = total number of features (in this case, streets in Wilmington). Drag this equation down a column = number of features in sample. Once this has been done, save/export (I usually like to use DBF for ArcGIS)

RANDBETWEEN(bottom,top)

Bottom is the smallest integer RANDBETWEEN will return.

Top is the largest integer RANDBETWEEN will return.

– with data added to ArcGIS, use “Frequency” tool to check that no duplicate values were generated

– do a regular one to one join, dropping out all values that don’t match. The result will be a random set of features — in this case, street segments.